The present invention relates to electronics assemblies, and is primarily concerned with racked assemblies. Many such assemblies will be located in racks for housing in for example nineteen inch cabinets, or other size cabinets such as twenty three inch or metric cabinets. The assemblies may for instance be employed as servers for a number of systems, for example in local area networks (LANS), wide area networks (WANs), telecommunications systems or other operations such as database management or as internet servers.
Such an assembly will typically comprise a supporting chassis that houses a motherboard or backplane and a number of daughterboards or module cards that extend in planes generally perpendicular to the plane of the motherboard and which are connected to the motherboard by connectors, e.g. high density connectors, so that the daughterboards can simply be located on guides and pushed toward the motherboard in order to connect them to it. An assembly will typically have dimensions in the order of 0.5 m in each direction and will be located in an enclosure, for example a cabinet, in an office, data centre, computer room or similar environment. Often, more than one such assembly is located in the same enclosure, and will need to be accessed from time to time for routine maintenance, repair or upgrading.
In order to enable a service engineer to access an assembly located in such an enclosure, the enclosure will normally comprise a supporting frame and a slider mechanism, one part of which is fixed on the supporting frame and the other part of which supports the electronics assembly, so that the assembly can be pulled out of the enclosure on the slider mechanism, and then, after work has been conducted on the assembly, can be pushed back into the enclosure. The slider mechanism will need to allow the assembly to be pulled out by at least the depth of the assembly, for example 0.5 m, in order to allow access to the rear parts thereof. The electronics assembly will usually have a large number of electrical cables, possibly including optical cables, extending from the rear thereof to the enclosure and beyond, and it is therefore necessary either to disconnect all interface and power cables whenever the assembly is withdrawn from the enclosure or to provide some form of cable management system that will support a service loop of cables having a length at least equal to the distance by which the assembly is moved as it is withdrawn from the enclosure.
Such cable management systems conventionally have taken the form of an articulated arm, one end of which is connected to the electronics assembly, and the other end of which is mounted on a rear part of the interior of the enclosure, so that the arm can accommodate movement of the assembly on the slider mechanism by bending and straightening. However, enclosures for such assemblies are manufactured in a range of different sizes. Their width is normally in the region of 19 inches (0.5 m), hence their name, but their depth can vary by quite a large degree, and it has been necessary to manufacture such cable management systems in a number of different sizes to suit the sizes of cabinets in which the assemblies are accommodated, or to manufacture the cable management systems with articulated arms of adjustable length, which adds to the complexity of the system. In addition, when such assemblies are located in relatively deep cabinets, the articulated arms of the cable management system are not fully bent when the assembly is fully inserted into the enclosure, which means that the distance the assembly can be pulled out of the enclosure is correspondingly reduced unless a more complex cable management system, for example involving articulated arms having three or more articulated members, is employed.